How Does the Birth Control Patch Work?
Medically reviewed by Mary Choy, PharmD
The birth control patch is a topical combined hormonal contraceptive method that contains synthetic forms of the hormones progesterone and estrogen. Commonly referred to as “the patch,” the Food and Drug Administration (FDA) initially approved this prescription medication in 2001 under the brand name Ortho Evra.
Hormonal contraceptives work by preventing ovulation and reducing the chance of pregnancy. However, unlike other hormonal methods, such as the pill, the patch requires the body to absorb the hormones through the skin into the bloodstream. This results in important differences between the patch and other hormonal birth control methods.
While Ortho Evra has been discontinued, generic versions are available. Other available brands include Xulane, Zafemy, and Twirla. Xulane, Zafemy, and their generic versions contain the same active ingredients: norelgestromin and ethinyl estradiol. Twirla, which currently has no generic version, contains the active ingredients levonorgestrel and ethinyl estradiol.
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About 65% of females ages 15 to 49 in the United States use a birth control method. In this group, the most popular methods for preventing pregnancy include tubal ligation, the pill, external condoms, and long-acting reversible contraception methods like intrauterine devices (IUDs).
This article will discuss the birth control patch, how it works, and other important information about using it safely and effectively.
A Note on Gender and Sex Terminology
Verywell Health acknowledges that sex and gender are related concepts, but they are not the same. To accurately reflect our sources, this article uses terms like “female,” “male,” “woman,” and “man” as the sources use them.
How Does the Birth Control Patch Work?
Regardless of its brand or generic name, all birth control patches work the same way. They contain a combination of two hormones: a progestin (either levonorgestrel or norelgestromin, which are both synthetic forms of progesterone) and an estrogen (ethinyl estradiol).
After properly applying the patch to your skin, the body absorbs these hormones through the skin and into the bloodstream. These hormones work to reduce the chance of pregnancy in three ways:
Preventing ovulation (the release of an egg from the ovary)
Thickening the cervical mucus, which limits sperm’s ability to reach an egg
Changing the lining of the uterus, which lowers the chance of a fertilized egg implanting
Combined oral contraceptive pills also contain a progestin and an estrogen component and work the same way. The main difference is that with the pill, you have to take it every day, while with the patch, you have to change it once a week.
How Quickly Does It Work?
Each birth control patch lasts for one week. The patch slowly releases the hormone ingredients, which are absorbed through your skin over the span of a week.
After a week, you’ll remove the patch and apply a new one to your skin. After three weeks, you’ll take a week off and get your period. You’ll repeat this process for as long as you prefer using the patch as your contraceptive method.
Keep in mind that birth control patches may not work immediately to prevent pregnancy. How long it takes to become fully effective depends on different factors, such as when you start using the patch, recent pregnancy, and whether you used another type of hormonal birth control, such as the pill, before starting the patch.
If you do not currently take hormonal birth control, there are two options for when to start using a birth control patch:
Day 1 start: Apply the first patch within 24 hours of when your period starts. In this case, the patch is immediately effective, and no backup contraception is required.
Sunday start: Apply the first patch on the first Sunday after your period starts. In this case, the patch takes about seven days to reach full effect. So, you should use a backup contraception method (such as condoms) for the first week after applying the first patch.
If you currently take hormonal birth control, starting a birth control patch is simple: apply the first patch when the next dose of birth control is due. The patch picks up where the other hormonal contraception left off, with no backup method necessary.
However, if more than one week has passed since your last dose of hormonal birth control, the patch takes about seven days to take effect, and backup methods are recommended.
After giving birth, you should wait at least four weeks or until you stop breastfeeding before starting a birth control patch. Then, you should use a backup method for the first week until the patch becomes fully effective.
This timeline differs if you’re starting the patch following a miscarriage or abortion. If you have a miscarriage or abortion during the first trimester, you can start using the birth control patch right afterward.
If you apply the patch within five days after the miscarriage or abortion, the patch will quickly reach its full effect, and no backup method is required. If more than five days pass, you should use a backup method until your next period.
However, if you have a miscarriage or abortion after the first trimester, you should wait four weeks before starting a birth control patch. It will then take seven days to reach maximum effect, so a backup method is recommended for the first week.
Other factors may affect how long it takes for the patch to work effectively. If you’re not sure, use a backup method or check with a healthcare provider.
How Effective Is It?
All methods of combined hormonal birth control, including the pill and the patch, are similarly effective at reducing the chance of pregnancy. In a trial of more than 3,000 people using the patch, only 15 pregnancies occurred during patch use, reflecting highly effective contraception.
With perfect use, the expected failure rate of the birth control patch is less than 1%. However, mistakes happen. Patches may fall off, or people forget to change them on time. As such, “typical use” of a birth control patch results in an expected failure rate between 6% and 7%.
Birth Control Patch: Uses and Availability
All birth control patches, also known as transdermal contraception, require a prescription from a healthcare provider. “The patch” is not a single product but refers to different products, including:
Product Name | Active Ingredients |
Ortho Evra (no longer available) | norelgestromin and ethinyl estradiol |
Xulane | norelgestromin and ethinyl estradiol |
Zafemy | norelgestromin and ethinyl estradiol |
Twirla | levonorgestrel and ethinyl estradiol |
norelgestromin and ethinyl estradiol (generic) | norelgestromin and ethinyl estradiol |
The FDA approves birth control patches to reduce the chance of pregnancy in females who can become pregnant and have a body mass index (BMI) of less than 30.
However, some healthcare providers prescribe medications “off label” for other reasons. For instance, some providers may recommend birth control, including the patch, for managing irregular menstrual cycles or treating hormone-related conditions like polycystic ovary syndrome (PCOS).
Applying a Birth Control Patch
Each birth control patch provides a week's supply of hormones necessary for preventing ovulation and reducing the chance of pregnancy. You should only wear one patch at a time and remove it after seven days.
The patch works best when placed on the outer portion of the upper arm, the abdomen, or the buttocks. Before applying the patch, ensure the area is clean, dry, and free of lotions or other products. When changing patches, place the new patch on a different spot.
You should avoid certain areas when placing a birth control patch. Never place the patch on your breast or any broken or irritated skin.
Applying a birth control patch is similar to applying an adhesive bandage. To apply the patch, press the patch firmly on the skin with the sticky side for 10 seconds. Inspect the patch carefully, smoothing out any wrinkles and ensuring the patch adheres to the skin all the way around its edges.
Inspect the patch once a day to ensure it stays in place. This is particularly important after sleeping, swimming, showering, or other activities that may loosen the patch.
Wear each patch continuously for seven days. This includes wearing the patch throughout all activities, including showering and sex. If a patch falls off, try putting it back on. If it doesn't stick, apply a new patch immediately. Then, remove the new patch on the same day that the original one would have been removed.
If more than a day passes without a patch on, place a new patch, but remove it after a full seven days instead.
Side Effects
Side effects may occur while using a birth control patch. Regardless of the brand or generic version you use, common side effects may include:
Breast tenderness
Irritation of the skin or other skin problems at the site of patch application
In some cases, those using a birth control patch experience more serious side effects. While uncommon, the severe side effects may include:
Increased risk of blood clots
Gallbladder problems, including gallstones
Ectopic pregnancy (a pregnancy occurring outside of the uterus)
Pneumonia (lung infection)
Gastroenteritis (stomach flu)
Birth control patches may be safely used long-term, as long as you regularly see a healthcare provider for monitoring and they confirm the product is safe for you to continue using.
Safely Using a Birth Control Patch
Birth control patches may not be safe for everyone. Healthcare providers do not recommend hormonal birth control for females over the age of 35 who smoke due to an increased risk of blood clots.
Similarly, females with a BMI of 30 or greater should not use the birth control patch, as studies found patches less effective and safe in this population.
A birth control patch may not be safe or appropriate for people with the following factors or conditions:
High risk of blood clots
Undiagnosed abnormal uterine bleeding
Certain migraine headache disorders
Pregnant or breastfeeding
Birth control patches may interact with other medications. Before starting any hormonal birth control patch, tell your healthcare provider all the medications and supplements you take to ensure the patch is safe for you.
Also, before starting any new medication or supplement, ask a healthcare provider whether it will affect the effectiveness or safety of the patch.
Some examples of medications that interact with birth control patches include:
Certain medications used to treat HIV, such as Norvir (ritonavir)
Some medications processed by the liver, including Diflucan (fluconazole)
Summary
Birth control patches are a type of hormonal contraceptive. The FDA approves the use of hormonal birth control patches to reduce the chance of pregnancy in females with a BMI of less than 30. Brand-name and generic options are available by prescription, including Xulane, Zafemy, and Twirla. The original brand, Otho Evra, has been discontinued.
Like other hormonal birth control methods, studies reflect that birth control patches provide a safe and effective method of contraception. When used perfectly, patches are more than 99% effective– but typical use by the average person results in a 6% to 7% failure rate.
Birth control patches contain two hormones: a progestin and an estrogen. After applying a patch, the body absorbs these hormones through the skin steadily over a week. These hormones work to halt ovulation, prevent sperm from reaching an egg, and limit the chances of fertilized egg implantation.
For the patch to work as intended, place the patch securely on your skin according to your healthcare provider's instructions. Forgetting to change your patch after a week or removing it too early reduces its effectiveness.
Birth control patches may not be a safe and effective contraceptive method for all females of reproductive potential. Talk to a healthcare provider to determine if the patch is right for you.
Frequently Asked Questions
How should a birth control patch be stored?
Store birth control patches at room temperature. Typically, each patch comes in an individually-wrapped pouch. Keep the patch in the unopened pouch until ready to use.
Can I smoke while using a birth control patch?
Smoking while using any type of hormonal contraception increases the risk of blood clots. This risk is highest in women aged 35 years and older who smoke. For this reason, the FDA recommends against the use of hormonal birth control patches in women ages 35 years and older who smoke.
What should I do if I forget to take a patch off?
It depends. If 48 hours or less have passed since the intended patch removal date, replace the patch and continue on the original timeline. However, if more than two days have passed since the intended patch removal day, restart the four-week cycle by placing a new patch and using backup contraception for at least seven days.
What should I do if I forget to put a patch on after the patch-free week?
In this case, you likely need additional protection to prevent pregnancy. Put on a new patch as soon as you remember, then restart a new four-week cycle. Use a backup contraceptive method for at least seven days after placing the new patch.
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